ipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT (Linux Linux)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.30 % · percentile 23 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Modified
Description
In the Linux kernel, the following vulnerability has been resolved: ipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT On PREEMPT_RT kernels, after rt6_get_pcpu_route() returns NULL, the current task can be preempted. Another task running on the same CPU may then execute rt6_make_pcpu_route() and successfully install a pcpu_rt entry. When the first task resumes execution, its cmpxchg() in rt6_make_pcpu_route() will fail because rt6i_pcpu is no longer NULL, triggering the BUG_ON(prev). It's easy to reproduce it by adding mdelay() after rt6_get_pcpu_route(). Using preempt_disable/enable is not appropriate here because ip6_rt_pcpu_alloc() may sleep. Fix this by handling the cmpxchg() failure gracefully on PREEMPT_RT: free our allocation and return the existing pcpu_rt installed by another task. The BUG_ON is replaced by WARN_ON_ONCE for non-PREEMPT_RT kernels where such races should not occur.
Weaknesses (CWE)
- CWE-617 — Reachable Assertion
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | Linux |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary) |
| CVSS 3.1 | MEDIUM 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H | NVD · nvd@nist.gov (Primary) |
European references
- ENISA EUVD · EUVD-2026-2250
- GCVE · GCVE-0-2025-71080
CERT-FR advisories
- CERTFR-2026-AVI-0602 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0495 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0453 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0421 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0247 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0225 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0170 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0166 — Multiples vulnérabilités dans le noyau Linux de Debian · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.12.1 < 6.12.64cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.13 < 6.18.4cpe:2.3:o:linux:linux_kernel:6.12:-:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.19:rc7:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:6.19:rc8:*:*:*:*:*:*
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected d2d6422f8bd17c6bb205133e290625a564194496 < 1dc33ad0867325f8d2c6d7b2a6f542d4f3121f66 ; affected d2d6422f8bd17c6bb205133e290625a564194496 < 787515ccb2292f82eb0876993129154629a49651 ; affected d2d6422f8bd17c6bb205133e290625a564194496 < 1adaea51c61b52e24e7ab38f7d3eba023b2d050d |
| Linux · Linux | affected 6.12 ; unaffected 0 < 6.12 ; unaffected 6.12.64 ≤ 6.12.* ; unaffected 6.18.4 ≤ 6.18.* ; unaffected 6.19 ≤ * |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |